1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7 * Copyright (C) 2002 Dominik Brodowski <devel@brodo.de>
8 *
9 * TBD:
10 * 1. Support more than one IRQ resource entry per link device (index).
11 * 2. Implement start/stop mechanism and use ACPI Bus Driver facilities
12 * for IRQ management (e.g. start()->_SRS).
13 */
14
15#define pr_fmt(fmt) "ACPI: PCI: " fmt
16
17#include <linux/syscore_ops.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/types.h>
22#include <linux/spinlock.h>
23#include <linux/pm.h>
24#include <linux/pci.h>
25#include <linux/mutex.h>
26#include <linux/slab.h>
27#include <linux/acpi.h>
28#include <linux/irq.h>
29
30#include "internal.h"
31
32#define ACPI_PCI_LINK_CLASS "pci_irq_routing"
33#define ACPI_PCI_LINK_DEVICE_NAME "PCI Interrupt Link"
34#define ACPI_PCI_LINK_MAX_POSSIBLE 16
35
36static int acpi_pci_link_add(struct acpi_device *device,
37 const struct acpi_device_id *not_used);
38static void acpi_pci_link_remove(struct acpi_device *device);
39
40static const struct acpi_device_id link_device_ids[] = {
41 {"PNP0C0F", 0},
42 {.id: "", .driver_data: 0},
43};
44
45static struct acpi_scan_handler pci_link_handler = {
46 .ids = link_device_ids,
47 .attach = acpi_pci_link_add,
48 .detach = acpi_pci_link_remove,
49};
50
51/*
52 * If a link is initialized, we never change its active and initialized
53 * later even the link is disable. Instead, we just repick the active irq
54 */
55struct acpi_pci_link_irq {
56 u32 active; /* Current IRQ */
57 u8 triggering; /* All IRQs */
58 u8 polarity; /* All IRQs */
59 u8 resource_type;
60 u8 possible_count;
61 u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
62 u8 initialized:1;
63 u8 reserved:7;
64};
65
66struct acpi_pci_link {
67 struct list_head list;
68 struct acpi_device *device;
69 struct acpi_pci_link_irq irq;
70 int refcnt;
71};
72
73static LIST_HEAD(acpi_link_list);
74static DEFINE_MUTEX(acpi_link_lock);
75static int sci_irq = -1, sci_penalty;
76
77/* --------------------------------------------------------------------------
78 PCI Link Device Management
79 -------------------------------------------------------------------------- */
80
81/*
82 * set context (link) possible list from resource list
83 */
84static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
85 void *context)
86{
87 struct acpi_pci_link *link = context;
88 acpi_handle handle = link->device->handle;
89 u32 i;
90
91 switch (resource->type) {
92 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
93 case ACPI_RESOURCE_TYPE_END_TAG:
94 return AE_OK;
95 case ACPI_RESOURCE_TYPE_IRQ:
96 {
97 struct acpi_resource_irq *p = &resource->data.irq;
98 if (!p->interrupt_count) {
99 acpi_handle_debug(handle,
100 "Blank _PRS IRQ resource\n");
101 return AE_OK;
102 }
103 for (i = 0;
104 (i < p->interrupt_count
105 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
106 if (!p->interrupts[i]) {
107 acpi_handle_debug(handle,
108 "Invalid _PRS IRQ %d\n",
109 p->interrupts[i]);
110 continue;
111 }
112 link->irq.possible[i] = p->interrupts[i];
113 link->irq.possible_count++;
114 }
115 link->irq.triggering = p->triggering;
116 link->irq.polarity = p->polarity;
117 link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
118 break;
119 }
120 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
121 {
122 struct acpi_resource_extended_irq *p =
123 &resource->data.extended_irq;
124 if (!p->interrupt_count) {
125 acpi_handle_debug(handle,
126 "Blank _PRS EXT IRQ resource\n");
127 return AE_OK;
128 }
129 for (i = 0;
130 (i < p->interrupt_count
131 && i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
132 if (!p->interrupts[i]) {
133 acpi_handle_debug(handle,
134 "Invalid _PRS IRQ %d\n",
135 p->interrupts[i]);
136 continue;
137 }
138 link->irq.possible[i] = p->interrupts[i];
139 link->irq.possible_count++;
140 }
141 link->irq.triggering = p->triggering;
142 link->irq.polarity = p->polarity;
143 link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
144 break;
145 }
146 default:
147 acpi_handle_debug(handle, "_PRS resource type 0x%x is not IRQ\n",
148 resource->type);
149 return AE_OK;
150 }
151
152 return AE_CTRL_TERMINATE;
153}
154
155static int acpi_pci_link_get_possible(struct acpi_pci_link *link)
156{
157 acpi_handle handle = link->device->handle;
158 acpi_status status;
159
160 status = acpi_walk_resources(device: handle, METHOD_NAME__PRS,
161 user_function: acpi_pci_link_check_possible, context: link);
162 if (ACPI_FAILURE(status)) {
163 acpi_handle_debug(handle, "_PRS not present or invalid");
164 return 0;
165 }
166
167 acpi_handle_debug(handle, "Found %d possible IRQs\n",
168 link->irq.possible_count);
169
170 return 0;
171}
172
173static acpi_status acpi_pci_link_check_current(struct acpi_resource *resource,
174 void *context)
175{
176 int *irq = context;
177
178 switch (resource->type) {
179 case ACPI_RESOURCE_TYPE_START_DEPENDENT:
180 case ACPI_RESOURCE_TYPE_END_TAG:
181 return AE_OK;
182 case ACPI_RESOURCE_TYPE_IRQ:
183 {
184 struct acpi_resource_irq *p = &resource->data.irq;
185 if (!p->interrupt_count) {
186 /*
187 * IRQ descriptors may have no IRQ# bits set,
188 * particularly those w/ _STA disabled
189 */
190 pr_debug("Blank _CRS IRQ resource\n");
191 return AE_OK;
192 }
193 *irq = p->interrupts[0];
194 break;
195 }
196 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
197 {
198 struct acpi_resource_extended_irq *p =
199 &resource->data.extended_irq;
200 if (!p->interrupt_count) {
201 /*
202 * extended IRQ descriptors must
203 * return at least 1 IRQ
204 */
205 pr_debug("Blank _CRS EXT IRQ resource\n");
206 return AE_OK;
207 }
208 *irq = p->interrupts[0];
209 break;
210 }
211 break;
212 default:
213 pr_debug("_CRS resource type 0x%x is not IRQ\n",
214 resource->type);
215 return AE_OK;
216 }
217
218 return AE_CTRL_TERMINATE;
219}
220
221/*
222 * Run _CRS and set link->irq.active
223 *
224 * return value:
225 * 0 - success
226 * !0 - failure
227 */
228static int acpi_pci_link_get_current(struct acpi_pci_link *link)
229{
230 acpi_handle handle = link->device->handle;
231 acpi_status status;
232 int result = 0;
233 int irq = 0;
234
235 link->irq.active = 0;
236
237 /* in practice, status disabled is meaningless, ignore it */
238 if (acpi_strict) {
239 /* Query _STA, set link->device->status */
240 result = acpi_bus_get_status(device: link->device);
241 if (result) {
242 acpi_handle_err(handle, "Unable to read status\n");
243 goto end;
244 }
245
246 if (!link->device->status.enabled) {
247 acpi_handle_debug(handle, "Link disabled\n");
248 return 0;
249 }
250 }
251
252 /*
253 * Query and parse _CRS to get the current IRQ assignment.
254 */
255
256 status = acpi_walk_resources(device: handle, METHOD_NAME__CRS,
257 user_function: acpi_pci_link_check_current, context: &irq);
258 if (ACPI_FAILURE(status)) {
259 acpi_evaluation_failure_warn(handle, name: "_CRS", status);
260 result = -ENODEV;
261 goto end;
262 }
263
264 if (acpi_strict && !irq) {
265 acpi_handle_err(handle, "_CRS returned 0\n");
266 result = -ENODEV;
267 }
268
269 link->irq.active = irq;
270
271 acpi_handle_debug(handle, "Link at IRQ %d\n", link->irq.active);
272
273 end:
274 return result;
275}
276
277static int acpi_pci_link_set(struct acpi_pci_link *link, int irq)
278{
279 struct {
280 struct acpi_resource res;
281 struct acpi_resource end;
282 } *resource;
283 struct acpi_buffer buffer = { 0, NULL };
284 acpi_handle handle = link->device->handle;
285 acpi_status status;
286 int result;
287
288 if (!irq)
289 return -EINVAL;
290
291 resource = kzalloc(sizeof(*resource) + 1, irqs_disabled() ? GFP_ATOMIC: GFP_KERNEL);
292 if (!resource)
293 return -ENOMEM;
294
295 buffer.length = sizeof(*resource) + 1;
296 buffer.pointer = resource;
297
298 switch (link->irq.resource_type) {
299 case ACPI_RESOURCE_TYPE_IRQ:
300 resource->res.type = ACPI_RESOURCE_TYPE_IRQ;
301 resource->res.length = sizeof(struct acpi_resource);
302 resource->res.data.irq.triggering = link->irq.triggering;
303 resource->res.data.irq.polarity =
304 link->irq.polarity;
305 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
306 resource->res.data.irq.shareable =
307 ACPI_EXCLUSIVE;
308 else
309 resource->res.data.irq.shareable = ACPI_SHARED;
310 resource->res.data.irq.interrupt_count = 1;
311 resource->res.data.irq.interrupts[0] = irq;
312 break;
313
314 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
315 resource->res.type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
316 resource->res.length = sizeof(struct acpi_resource);
317 resource->res.data.extended_irq.producer_consumer =
318 ACPI_CONSUMER;
319 resource->res.data.extended_irq.triggering =
320 link->irq.triggering;
321 resource->res.data.extended_irq.polarity =
322 link->irq.polarity;
323 if (link->irq.triggering == ACPI_EDGE_SENSITIVE)
324 resource->res.data.extended_irq.shareable =
325 ACPI_EXCLUSIVE;
326 else
327 resource->res.data.extended_irq.shareable = ACPI_SHARED;
328 resource->res.data.extended_irq.interrupt_count = 1;
329 resource->res.data.extended_irq.interrupts[0] = irq;
330 /* ignore resource_source, it's optional */
331 break;
332 default:
333 acpi_handle_err(handle, "Invalid resource type %d\n",
334 link->irq.resource_type);
335 result = -EINVAL;
336 goto end;
337
338 }
339 resource->end.type = ACPI_RESOURCE_TYPE_END_TAG;
340 resource->end.length = sizeof(struct acpi_resource);
341
342 /* Attempt to set the resource */
343 status = acpi_set_current_resources(device: link->device->handle, in_buffer: &buffer);
344
345 /* check for total failure */
346 if (ACPI_FAILURE(status)) {
347 acpi_evaluation_failure_warn(handle, name: "_SRS", status);
348 result = -ENODEV;
349 goto end;
350 }
351
352 /* Query _STA, set device->status */
353 result = acpi_bus_get_status(device: link->device);
354 if (result) {
355 acpi_handle_err(handle, "Unable to read status\n");
356 goto end;
357 }
358 if (!link->device->status.enabled)
359 acpi_handle_warn(handle, "Disabled and referenced, BIOS bug\n");
360
361 /* Query _CRS, set link->irq.active */
362 result = acpi_pci_link_get_current(link);
363 if (result) {
364 goto end;
365 }
366
367 /*
368 * Is current setting not what we set?
369 * set link->irq.active
370 */
371 if (link->irq.active != irq) {
372 /*
373 * policy: when _CRS doesn't return what we just _SRS
374 * assume _SRS worked and override _CRS value.
375 */
376 acpi_handle_warn(handle, "BIOS reported IRQ %d, using IRQ %d\n",
377 link->irq.active, irq);
378 link->irq.active = irq;
379 }
380
381 acpi_handle_debug(handle, "Set IRQ %d\n", link->irq.active);
382
383 end:
384 kfree(objp: resource);
385 return result;
386}
387
388/* --------------------------------------------------------------------------
389 PCI Link IRQ Management
390 -------------------------------------------------------------------------- */
391
392/*
393 * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
394 * Link Devices to move the PIRQs around to minimize sharing.
395 *
396 * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
397 * that the BIOS has already set to active. This is necessary because
398 * ACPI has no automatic means of knowing what ISA IRQs are used. Note that
399 * if the BIOS doesn't set a Link Device active, ACPI needs to program it
400 * even if acpi_irq_nobalance is set.
401 *
402 * A tables of penalties avoids directing PCI interrupts to well known
403 * ISA IRQs. Boot params are available to over-ride the default table:
404 *
405 * List interrupts that are free for PCI use.
406 * acpi_irq_pci=n[,m]
407 *
408 * List interrupts that should not be used for PCI:
409 * acpi_irq_isa=n[,m]
410 *
411 * Note that PCI IRQ routers have a list of possible IRQs,
412 * which may not include the IRQs this table says are available.
413 *
414 * Since this heuristic can't tell the difference between a link
415 * that no device will attach to, vs. a link which may be shared
416 * by multiple active devices -- it is not optimal.
417 *
418 * If interrupt performance is that important, get an IO-APIC system
419 * with a pin dedicated to each device. Or for that matter, an MSI
420 * enabled system.
421 */
422
423#define ACPI_MAX_ISA_IRQS 16
424
425#define PIRQ_PENALTY_PCI_POSSIBLE (16*16)
426#define PIRQ_PENALTY_PCI_USING (16*16*16)
427#define PIRQ_PENALTY_ISA_TYPICAL (16*16*16*16)
428#define PIRQ_PENALTY_ISA_USED (16*16*16*16*16)
429#define PIRQ_PENALTY_ISA_ALWAYS (16*16*16*16*16*16)
430
431static int acpi_isa_irq_penalty[ACPI_MAX_ISA_IRQS] = {
432 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ0 timer */
433 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ1 keyboard */
434 PIRQ_PENALTY_ISA_ALWAYS, /* IRQ2 cascade */
435 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ3 serial */
436 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ4 serial */
437 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ5 sometimes SoundBlaster */
438 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ6 */
439 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ7 parallel, spurious */
440 PIRQ_PENALTY_ISA_TYPICAL, /* IRQ8 rtc, sometimes */
441 0, /* IRQ9 PCI, often acpi */
442 0, /* IRQ10 PCI */
443 0, /* IRQ11 PCI */
444 PIRQ_PENALTY_ISA_USED, /* IRQ12 mouse */
445 PIRQ_PENALTY_ISA_USED, /* IRQ13 fpe, sometimes */
446 PIRQ_PENALTY_ISA_USED, /* IRQ14 ide0 */
447 PIRQ_PENALTY_ISA_USED, /* IRQ15 ide1 */
448 /* >IRQ15 */
449};
450
451static int acpi_irq_pci_sharing_penalty(int irq)
452{
453 struct acpi_pci_link *link;
454 int penalty = 0;
455 int i;
456
457 list_for_each_entry(link, &acpi_link_list, list) {
458 /*
459 * If a link is active, penalize its IRQ heavily
460 * so we try to choose a different IRQ.
461 */
462 if (link->irq.active && link->irq.active == irq)
463 penalty += PIRQ_PENALTY_PCI_USING;
464
465 /*
466 * penalize the IRQs PCI might use, but not as severely.
467 */
468 for (i = 0; i < link->irq.possible_count; i++)
469 if (link->irq.possible[i] == irq)
470 penalty += PIRQ_PENALTY_PCI_POSSIBLE /
471 link->irq.possible_count;
472 }
473
474 return penalty;
475}
476
477static int acpi_irq_get_penalty(int irq)
478{
479 int penalty = 0;
480
481 if (irq == sci_irq)
482 penalty += sci_penalty;
483
484 if (irq < ACPI_MAX_ISA_IRQS)
485 return penalty + acpi_isa_irq_penalty[irq];
486
487 return penalty + acpi_irq_pci_sharing_penalty(irq);
488}
489
490int __init acpi_irq_penalty_init(void)
491{
492 struct acpi_pci_link *link;
493 int i;
494
495 /*
496 * Update penalties to facilitate IRQ balancing.
497 */
498 list_for_each_entry(link, &acpi_link_list, list) {
499
500 /*
501 * reflect the possible and active irqs in the penalty table --
502 * useful for breaking ties.
503 */
504 if (link->irq.possible_count) {
505 int penalty =
506 PIRQ_PENALTY_PCI_POSSIBLE /
507 link->irq.possible_count;
508
509 for (i = 0; i < link->irq.possible_count; i++) {
510 if (link->irq.possible[i] < ACPI_MAX_ISA_IRQS)
511 acpi_isa_irq_penalty[link->irq.
512 possible[i]] +=
513 penalty;
514 }
515
516 } else if (link->irq.active &&
517 (link->irq.active < ACPI_MAX_ISA_IRQS)) {
518 acpi_isa_irq_penalty[link->irq.active] +=
519 PIRQ_PENALTY_PCI_POSSIBLE;
520 }
521 }
522
523 return 0;
524}
525
526static int acpi_irq_balance = -1; /* 0: static, 1: balance */
527
528static int acpi_pci_link_allocate(struct acpi_pci_link *link)
529{
530 acpi_handle handle = link->device->handle;
531 int irq;
532 int i;
533
534 if (link->irq.initialized) {
535 if (link->refcnt == 0)
536 /* This means the link is disabled but initialized */
537 acpi_pci_link_set(link, irq: link->irq.active);
538 return 0;
539 }
540
541 /*
542 * search for active IRQ in list of possible IRQs.
543 */
544 for (i = 0; i < link->irq.possible_count; ++i) {
545 if (link->irq.active == link->irq.possible[i])
546 break;
547 }
548 /*
549 * forget active IRQ that is not in possible list
550 */
551 if (i == link->irq.possible_count) {
552 if (acpi_strict)
553 acpi_handle_warn(handle, "_CRS %d not found in _PRS\n",
554 link->irq.active);
555 link->irq.active = 0;
556 }
557
558 /*
559 * if active found, use it; else pick entry from end of possible list.
560 */
561 if (link->irq.active)
562 irq = link->irq.active;
563 else
564 irq = link->irq.possible[link->irq.possible_count - 1];
565
566 if (acpi_irq_balance || !link->irq.active) {
567 /*
568 * Select the best IRQ. This is done in reverse to promote
569 * the use of IRQs 9, 10, 11, and >15.
570 */
571 for (i = (link->irq.possible_count - 1); i >= 0; i--) {
572 if (acpi_irq_get_penalty(irq) >
573 acpi_irq_get_penalty(irq: link->irq.possible[i]))
574 irq = link->irq.possible[i];
575 }
576 }
577 if (acpi_irq_get_penalty(irq) >= PIRQ_PENALTY_ISA_ALWAYS) {
578 acpi_handle_err(handle,
579 "No IRQ available. Try pci=noacpi or acpi=off\n");
580 return -ENODEV;
581 }
582
583 /* Attempt to enable the link device at this IRQ. */
584 if (acpi_pci_link_set(link, irq)) {
585 acpi_handle_err(handle,
586 "Unable to set IRQ. Try pci=noacpi or acpi=off\n");
587 return -ENODEV;
588 } else {
589 if (link->irq.active < ACPI_MAX_ISA_IRQS)
590 acpi_isa_irq_penalty[link->irq.active] +=
591 PIRQ_PENALTY_PCI_USING;
592
593 acpi_handle_info(handle, "Enabled at IRQ %d\n",
594 link->irq.active);
595 }
596
597 link->irq.initialized = 1;
598 return 0;
599}
600
601/*
602 * acpi_pci_link_allocate_irq
603 * success: return IRQ >= 0
604 * failure: return -1
605 */
606int acpi_pci_link_allocate_irq(acpi_handle handle, int index, int *triggering,
607 int *polarity, char **name)
608{
609 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
610 struct acpi_pci_link *link;
611
612 if (!device) {
613 acpi_handle_err(handle, "Invalid link device\n");
614 return -1;
615 }
616
617 link = acpi_driver_data(d: device);
618 if (!link) {
619 acpi_handle_err(handle, "Invalid link context\n");
620 return -1;
621 }
622
623 /* TBD: Support multiple index (IRQ) entries per Link Device */
624 if (index) {
625 acpi_handle_err(handle, "Invalid index %d\n", index);
626 return -1;
627 }
628
629 mutex_lock(lock: &acpi_link_lock);
630 if (acpi_pci_link_allocate(link)) {
631 mutex_unlock(lock: &acpi_link_lock);
632 return -1;
633 }
634
635 if (!link->irq.active) {
636 mutex_unlock(lock: &acpi_link_lock);
637 acpi_handle_err(handle, "Link active IRQ is 0!\n");
638 return -1;
639 }
640 link->refcnt++;
641 mutex_unlock(lock: &acpi_link_lock);
642
643 if (triggering)
644 *triggering = link->irq.triggering;
645 if (polarity)
646 *polarity = link->irq.polarity;
647 if (name)
648 *name = acpi_device_bid(link->device);
649 acpi_handle_debug(handle, "Link is referenced\n");
650 return link->irq.active;
651}
652
653/*
654 * We don't change link's irq information here. After it is reenabled, we
655 * continue use the info
656 */
657int acpi_pci_link_free_irq(acpi_handle handle)
658{
659 struct acpi_device *device = acpi_fetch_acpi_dev(handle);
660 struct acpi_pci_link *link;
661
662 if (!device) {
663 acpi_handle_err(handle, "Invalid link device\n");
664 return -1;
665 }
666
667 link = acpi_driver_data(d: device);
668 if (!link) {
669 acpi_handle_err(handle, "Invalid link context\n");
670 return -1;
671 }
672
673 mutex_lock(lock: &acpi_link_lock);
674 if (!link->irq.initialized) {
675 mutex_unlock(lock: &acpi_link_lock);
676 acpi_handle_err(handle, "Link isn't initialized\n");
677 return -1;
678 }
679#ifdef FUTURE_USE
680 /*
681 * The Link reference count allows us to _DISable an unused link
682 * and suspend time, and set it again on resume.
683 * However, 2.6.12 still has irq_router.resume
684 * which blindly restores the link state.
685 * So we disable the reference count method
686 * to prevent duplicate acpi_pci_link_set()
687 * which would harm some systems
688 */
689 link->refcnt--;
690#endif
691 acpi_handle_debug(handle, "Link is dereferenced\n");
692
693 if (link->refcnt == 0)
694 acpi_evaluate_object(object: link->device->handle, pathname: "_DIS", NULL, NULL);
695
696 mutex_unlock(lock: &acpi_link_lock);
697 return link->irq.active;
698}
699
700/* --------------------------------------------------------------------------
701 Driver Interface
702 -------------------------------------------------------------------------- */
703
704static int acpi_pci_link_add(struct acpi_device *device,
705 const struct acpi_device_id *not_used)
706{
707 acpi_handle handle = device->handle;
708 struct acpi_pci_link *link;
709 int result;
710 int i;
711
712 link = kzalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
713 if (!link)
714 return -ENOMEM;
715
716 link->device = device;
717 strscpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
718 strscpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
719 device->driver_data = link;
720
721 mutex_lock(lock: &acpi_link_lock);
722 result = acpi_pci_link_get_possible(link);
723 if (result)
724 goto end;
725
726 /* query and set link->irq.active */
727 acpi_pci_link_get_current(link);
728
729 pr_info("Interrupt link %s configured for IRQ %d\n",
730 acpi_device_bid(device), link->irq.active);
731
732 for (i = 0; i < link->irq.possible_count; i++) {
733 if (link->irq.active != link->irq.possible[i])
734 acpi_handle_debug(handle, "Possible IRQ %d\n",
735 link->irq.possible[i]);
736 }
737
738 if (!link->device->status.enabled)
739 pr_info("Interrupt link %s disabled\n", acpi_device_bid(device));
740
741 list_add_tail(new: &link->list, head: &acpi_link_list);
742
743 end:
744 /* disable all links -- to be activated on use */
745 acpi_evaluate_object(object: handle, pathname: "_DIS", NULL, NULL);
746 mutex_unlock(lock: &acpi_link_lock);
747
748 if (result)
749 kfree(objp: link);
750
751 acpi_dev_clear_dependencies(supplier: device);
752
753 return result < 0 ? result : 1;
754}
755
756static int acpi_pci_link_resume(struct acpi_pci_link *link)
757{
758 if (link->refcnt && link->irq.active && link->irq.initialized)
759 return (acpi_pci_link_set(link, irq: link->irq.active));
760
761 return 0;
762}
763
764static void irqrouter_resume(void)
765{
766 struct acpi_pci_link *link;
767
768 list_for_each_entry(link, &acpi_link_list, list) {
769 acpi_pci_link_resume(link);
770 }
771}
772
773static void acpi_pci_link_remove(struct acpi_device *device)
774{
775 struct acpi_pci_link *link;
776
777 link = acpi_driver_data(d: device);
778
779 mutex_lock(lock: &acpi_link_lock);
780 list_del(entry: &link->list);
781 mutex_unlock(lock: &acpi_link_lock);
782
783 kfree(objp: link);
784}
785
786/*
787 * modify acpi_isa_irq_penalty[] from cmdline
788 */
789static int __init acpi_irq_penalty_update(char *str, int used)
790{
791 int i;
792
793 for (i = 0; i < 16; i++) {
794 int retval;
795 int irq;
796 int new_penalty;
797
798 retval = get_option(str: &str, pint: &irq);
799
800 if (!retval)
801 break; /* no number found */
802
803 /* see if this is a ISA IRQ */
804 if ((irq < 0) || (irq >= ACPI_MAX_ISA_IRQS))
805 continue;
806
807 if (used)
808 new_penalty = acpi_isa_irq_penalty[irq] +
809 PIRQ_PENALTY_ISA_USED;
810 else
811 new_penalty = 0;
812
813 acpi_isa_irq_penalty[irq] = new_penalty;
814 if (retval != 2) /* no next number */
815 break;
816 }
817 return 1;
818}
819
820/*
821 * We'd like PNP to call this routine for the
822 * single ISA_USED value for each legacy device.
823 * But instead it calls us with each POSSIBLE setting.
824 * There is no ISA_POSSIBLE weight, so we simply use
825 * the (small) PCI_USING penalty.
826 */
827void acpi_penalize_isa_irq(int irq, int active)
828{
829 if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
830 acpi_isa_irq_penalty[irq] +=
831 (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
832}
833
834bool acpi_isa_irq_available(int irq)
835{
836 return irq >= 0 && (irq >= ARRAY_SIZE(acpi_isa_irq_penalty) ||
837 acpi_irq_get_penalty(irq) < PIRQ_PENALTY_ISA_ALWAYS);
838}
839
840void acpi_penalize_sci_irq(int irq, int trigger, int polarity)
841{
842 sci_irq = irq;
843
844 if (trigger == ACPI_MADT_TRIGGER_LEVEL &&
845 polarity == ACPI_MADT_POLARITY_ACTIVE_LOW)
846 sci_penalty = PIRQ_PENALTY_PCI_USING;
847 else
848 sci_penalty = PIRQ_PENALTY_ISA_ALWAYS;
849}
850
851/*
852 * Over-ride default table to reserve additional IRQs for use by ISA
853 * e.g. acpi_irq_isa=5
854 * Useful for telling ACPI how not to interfere with your ISA sound card.
855 */
856static int __init acpi_irq_isa(char *str)
857{
858 return acpi_irq_penalty_update(str, used: 1);
859}
860
861__setup("acpi_irq_isa=", acpi_irq_isa);
862
863/*
864 * Over-ride default table to free additional IRQs for use by PCI
865 * e.g. acpi_irq_pci=7,15
866 * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
867 */
868static int __init acpi_irq_pci(char *str)
869{
870 return acpi_irq_penalty_update(str, used: 0);
871}
872
873__setup("acpi_irq_pci=", acpi_irq_pci);
874
875static int __init acpi_irq_nobalance_set(char *str)
876{
877 acpi_irq_balance = 0;
878 return 1;
879}
880
881__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
882
883static int __init acpi_irq_balance_set(char *str)
884{
885 acpi_irq_balance = 1;
886 return 1;
887}
888
889__setup("acpi_irq_balance", acpi_irq_balance_set);
890
891static struct syscore_ops irqrouter_syscore_ops = {
892 .resume = irqrouter_resume,
893};
894
895void __init acpi_pci_link_init(void)
896{
897 if (acpi_noirq)
898 return;
899
900 if (acpi_irq_balance == -1) {
901 /* no command line switch: enable balancing in IOAPIC mode */
902 if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC)
903 acpi_irq_balance = 1;
904 else
905 acpi_irq_balance = 0;
906 }
907 register_syscore_ops(ops: &irqrouter_syscore_ops);
908 acpi_scan_add_handler(handler: &pci_link_handler);
909}
910